Title

Effect of crowding on Spirodela growth.

Problem Scenario

I chose this experiment because I wanted to know if crowding would effect the growth of Spirodela in a positive way or a negative way.

Broad Question

Would crowding effect a plants growth?

Specific Question

What is the effect of crowding on the growth of Spirodela?

Hypothesis

I think the non-crowded Spirodela will grow faster than the crowded Spirodela.

Graph of Hypothesis

Variables

Independent Variable:

Plant spacing.

Dependent Variable:

Number of Spirodela plants in the end.

Variables That Need To Be Controlled:

Size of cup
Size of screen
Enviroment
Amount of water
Number of cups

Vocabulary List That Needs Explanation

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General Plan

1. Set up the containers of crowded and non-crowded Spirodela.
2. Count the number if individual plants in each cup.
3. Record data in science notebook each day.

Potential Problems And Solutions

If the Spirodela dies i will have to just somehow add that into my data.

Safety Or Environmental Concerns

Experimental Design

Number Of Trials:

I did one trial.

Number Of Subjects In Each trial:

I had two subjects in each trial.

When data will be collected

My data will be collected everyday for fifteen days.

Number of Observations:

I have tree observations.

Where will data be collected?:

My data will be collected in my science notebook.

Resources and Budget Table

Screen	Mr.Biche	$0.00
Straws	Home	$0.00
Poster Board	Staples	$5.00

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Background Research

Two free-floating aquatic plants Eichhornia crassipes and Pistia stratiotes were investigated using a replacement series for the intermixed combinations. The carrying capacity for each plant was investigated in monoculture. The Eichhornia crassipes plant showed dominance over the Pistia stratiotes plant when the two plants were grown together. within the first month the interaction between the two plants became noticeable.
Three species of small, free-floating, aquatic plants in a beaver swamp were monitored for a year. In the summer Salvinia Minima grew rapidly and negatively affected the cover of both Azolla Caroliniana and Spirodela Punctata. Minima would increase when it grew with Punctata.
In Autumn Minima had a negative effect on Caroliniana’s increase of cover. However this effect was not competitive. It was caused by herbivore of Minima that switched to Caroliniana as’s growth slowed in Autumn. Minima is a better competitor in the Summer.
Hydrilla an exotic submersed aquatic plant was introduced to Florida in the late 1950’s and is now a gigantic weed problem. Once Hydrilla produced as much dry plant weight during a sixteen week period as sixteen tips planted under the same conditions. The dry weight of the plants after sixteen weeks were as high as 1,561 times that of the shoot tips that were planted.

References

• Matthew B. Dickinson and Thomas E. Miller

The American Midland Naturalist 1998 140 (1), 55-67

• M. Agami, K.R. Reddy, Competition for space between Eichhornia crassipes (Mart.) Solms and Pistia stratiotes L. cultured in nutrient-enriched water, Aquatic Botany, Volume 38, Issues 2–3, November 1990, Pages 195-208, ISSN 0304-3770, 10.1016/0304-3770(90)90005-6. (http://www.sciencedirect.com/science/article/pii/0304377090900056)
• David L. Sutton, R. C. Littell and K. A. Langeland Weed Science Vol. 28, No. 4 (Jul., 1980), pp. 425-428. Weed Science Society of America.

Detailed Procedure

1: I made the raft that the Spirodela would be placed in.
2: I filled the containers almost to the top with water and placed the raft in them.
3: Then I placed six individual Spirodela in each container. Two containers with crowded Spirodela and two containers with non-crowded Spirodela.
4: Counted the number of each individual plants in each container.

Diagram

Photo List

Non-crowded cup 1 Non-crowded cup 2 Crowded cup 1 Crowded cup 2

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Results

All Raw Data

non-crowded cup 1	non-crowded cup 2	crowded cup 1	crowded cup 2
17 Spirodela	19 Spirodela	9 Spirodela	17 Spirodela

Graphs

Photos

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Data Analysis

When I started my experiment I had six Spirodela plants set up in each container. After a few days the plants increased by e few individuals. Sometimes the plants did not increase for a few days at a time. In the middle of the experiment I could not tell if crowding would affect the growth of the plants. In the end of the experiment I still could not tell if crowding had an affect on plant growth until I put the data into a graph.

Conclusion

My hypothesis that the non-crowded Spirodela will grow faster than the crowded Spirodela came true. The non-crowded Spirodela plants did grow better then the crowded Plants.

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Discussion

My data showed that both containers for the most part had around the same number of Spirodela in them. I was able to answer my experimental question by the end of my experiment. My answer was that crowding does have a small effect on the growth of the Spirodela. My experiment did not have any errors throughout the whole thing. My data also did not have any errors in it. I could have added more containers to make my experiment better. I also could have done another container with a different common aquatic plant to see if that would effect the growth of the plants.

Benefit to Community and/or Science

This experiment could help the community because their are some people who will place things in ponds or lakes that shouldn't be their and if its something like Spirodela it's important to know how the condition the plants in will effect it's growth. This experiment could help science because if something happens to a lake or a pond it would be nice to know how it will grow in certain situations. This could also help scientist's figure out how to get rid of an invasive aquatic plant.

Abstract

I chose this experiment because I know someone who has a job extracting mill foil from lakes and I know that that plant is very invasive., but I do not know if crowding had any effect on the plant So I wanted to see if other aquatic plants like Spirodela could grow better in crowded areas or non-crowded areas. When I first started my experiment I was sure that Spirodela would grow better in non-crowded areas. And after a week or so it looked like i was going to be right, but after two weeks it was getting harder to tell because the number of individual plant in each container were really close. By the end of my experiment I found out that I was right and that crowding did have an effect on Spirodela growth, but just a small effect.